[Modes of treatment for arteriovenous malformations of the brain]. / Modalidades de tratamiento de las malformaciones arteriovenosas cerebrales.

INTRODUCTION AND DEVELOPMENT: Over the years new kinds of therapy have been incorporated into the treatment of arteriovenous malformations (AVM). Current treatment of AVM of the brain employs three well established options: radiosurgery, endovascular therapy (embolisation) and microsurgical resection. Radiosurgery is the simplest and least invasive, but 2 3 years are required to achieve total obliteration, and throughout this time there is the risk of bleeding; its use is limited to small AVM. Embolisation today plays a fundamental role more as an adjunct than when it is associated, although the other modes improve their cure interval by 25%. Microsurgery has the advantage of being the only mode of therapy that offers a degree of immediate angiographic obliteration of almost 100% and is still the most widely employed, despite its morbidity rate also being the highest. We establish an AVM management algorithm, in which, according to the size and localisation, we suggest that these therapeutic options should be used alone or in combination. CONCLUSIONS: The management of these lesions requires a combined effort of all the factors that can be of any help in the solution, and these modes are more complementary than competitive in situations in which they are all valid therapeutic options.

[The diagnosis of arteriovenous malformations of the brain]. / Diagnóstico de las malformaciones arteriovenosas cerebrales.

INTRODUCTION: Arteriovenous malformations (AVM) of the brain are, at present, entities that are difficult to diagnose owing to the variations in their clinical presentation and the different localisations in the central nervous system. Their most frequent clinical forms are haemorrhage, which is typically located in the intraparenchymatous region, seizures and, less frequently, vascular headache and progressive neurological deficit. DEVELOPMENT AND CONCLUSIONS: Several imaging studies with different resolutions must be performed for a final and conclusive diagnosis of an AVM, and brain angiography remains the first choice procedure, both in diagnosis and in planning management. The more recent use of functional studies has enabled us to better evaluate the haemodynamic characters of AVM and the repercussion on the surrounding brain tissue. The use of transoperative angiography, as a complement in resective surgery, allows us to determine the level of resection before closing the skull and, thus, to correct technical defects. It therefore diminishes the post operative complications derived from remnants of the lesion.

[Subthalamic nucleus targeting and spatial variability]. / Localización bilateral y simetría del núcleo subtalámico.

AIM: The effectiveness of anatomic localization of the subthalamic nucleus (EAL) was assessed and the mapping method is described here. The symmetry of contralateral nuclei (SCN) was analyzed on 11 parkinsonian patients submitted to bilateral subthalamotomy with ablative lesioning. PATIENTS AND METHODS: To assess EAL the percentage so much of first trajectory (p1) as the total of trajectories (pt) that hit the target and the rest of subthalamic nucleus average distance (d) was calculated. The anatomic localization error (epsilon) is determined as a difference between first trajectory coordinates with those of medial determined nucleus point, through electrophysiological data as to the statistical significance of this error. SCN is analyzed by contrasting equality hypothesis at the nucleus maximum height alongside a trajectory, average electrophysiological position center and spatial distribution of all intranuclear recordings found in each hemisphere in all patients. RESULTS: The pi, pt and d obtained values were 86.36%, 86.13% and 1.41 +/- 1.01 mm respectively. The epsilon value was greater in anteroposterior direction of 1.11 +/- 0.83 mm without statistical significance. The average number of recorded trajectories for the first procedure was 6.45 and 6 for the second. The asymmetry of contralateral nucleus was not significant. CONCLUSIONS: An indirect method with CT brain images and a new electrophysiological mapping method with a multiunitary recording for first and second nucleus is safe enough and it yields a high effectiveness in anatomofunctional nucleus localization. The nucleus of a same patient are symmetrical. There is little space variability among patient non related to the differences in the intercommissural distance.

[Osteochondroma of the atlantooccipital joint. Extreme lateral transcondylar approach. A case description]. / Osteocondroma de la articulación atlantoccipital. Abordaje extremo lateral transcondilar. A propósito de un caso.

INTRODUCTION: We describe a patient diagnosed as suffering from a skull base osteochondroma which affected the atlantooccipital joint and originated in the occipital condyle. It also displayed a growth toward the foramen magnum, which was resected using an extreme lateral transcondylar approach. CASE REPORT: Patient aged 35, with a one year history of vertiginous seizures and unsteady gait, associated with cervical pain that irradiated to the right upper extremity, dysphagia, changes in the tone of the voice and distal numbness of the four extremities. The patient was made to lie in the three quarter prone position and an incision was made in the skin from the C3 spinous apophysis to a point 2 cm below the end of the mastoid process, in relation with the transversal apophysis of C1. The intervention continued with early identification and rotation of the vertebral artery; total resection of the tumour (osteochondroma) with its base in the right occipital condyle and growth toward the foramen magnum, in which the greater resection of the posteromedial third of the condyle is included. CONCLUSIONS: The location of osteochondromas can vary widely, and the condyle is one of the least frequent places inside the occipital bone. The approach employed provides excellent access to the region, in particular to the atlantooccipital joint. The width and angle of exposition are increased as compared with the traditional suboccipital approach, which facilitates the radical resection of the lesion with no neural retraction and without any surgical complications.

[Penetrating head injury from harpoon. Case report]. / Trauma craneoencefálico perforante por arpón. Precentación de un caso y revisión de la literatura.

The harpoon presence as aggressor weapon is unusual in the neurosurgical practice. Most cases are associated with diving or sport activities as result of imprudence. A 31 year old patient who sustained a penetrating craniocerebral injury with a fishing harpoon is presented and complementary exams, neurosurgical procedure and postoperative evolution are detailed. We discuss the management of this unusual injury and review the current literature on craniocerebral injuries caused by similar objects.

[Presentation of distal saccular aneurysm as a subdural haematoma]. / Aneurisma sacular distal presentándose como hematoma subdural.

INTRODUCTION: Intracranial aneurysms are one of the most frequent vascular diseases. Nevertheless, saccular aneurysms that are not due to an inflammatory aetiology, which are located in the peripheral segment of the posterior circulation, are extremely rare. They are most frequently located in the thickest arterial branches within the region of the anterior brain circulation, as is the case of the complex made up of the anterior cerebral artery posterior communicating artery, middle cerebral artery and posterior communicating artery. No clinical manifestations are produced in many of these aneurysms, and their rupture and the subsequent development of a subarachnoid haemorrhage is the cause of the most intense neurological damage, which on occasions can lead to fatal consequences. CASE REPORT: We report the case of a patient who was a carrier of distal aneurysm, located in the posterior region of the brain circulation, and also the neuroradiological findings, the form of clinical presentation and surgical treatment carried out, which allowed us to identify and close the afferent vessel and the resection of the aneurysmatic sac. CONCLUSION: From the presentation of the symptoms of this patient in the form of a subarachnoid haemorrhage, accompanied by a subdural haematoma, it could be inferred that these clinical and imagenological findings point to the rupture of a distal aneurysm. Application of the stereotactic approach would be one of the first choice treatments for aneurysms in the distal region if we bear in mind the characteristics of the afferent vessel, the size of the neck and the morphology of the sac

[Direct approach to carotid cavernosa fistula type of arterio venous dural malformation. Case report and review of the literature]. / Abordaje directo de la malformaci n arteriovenosa dural tipo fistula carotidacavernosa. Presentaci n de un caso y revisi n de la literatura.

OBJECTIVES: Barrow's D type carotid cavernosa fistula (FCC) with progressive symptoms and in whom endovascular procedures have failed meet criteria for a direct approach. We report a case of this type of vascular lesion in whom partial endovascular embolization was done together with a direct approach to the FCC, using a method of localization involving a transoperative imaging guide. Digital subtraction angiography and Estereoflex stereotactic system was used. PATIENTS AND METHODS: A female patient had had a previous minor head injury. She had a progressive neurological disorder with marked visual defect, and had been diagnosed on angiography as having FCC with afferents from branches of the internal carotid artery (ACI) and external carotid artery (ACE). After failure of endovascular treatment orbito zygomatic craniotomy was done with extra intradural dissection and exposure of the antero lateral triangle of the cavernous sinus (SC). The fistula was closed completely by anterior packing with the venous component. Transoperative stereotactic angiographic checks were done to localize and control the packing. CONCLUSIONS: The Barrow's type D FCC in which embolization treatment has failed may be treated using a direct approach to the anterolateral triangle of the SC. The AC1 remained permeable, fistula was occluded and there was minimal morbidity.